1. Technical Field of the Invention
The present invention relates to a mask, a substrate with a light reflection film, a manufacturing method for a light reflection film, a manufacturing method for an electro-optical device, and an electro-optical device, and an electronic apparatus.
For further details, the present invention relates to a mask for producing a substrate with light reflection film which brings about few interference fringes, a substrate with light reflection film using the same, a manufacturing method for a light reflection film, and an electro-optical device provided with the substrate with light reflection film which brings about few interference fringes, and an electronic apparatus provided with the substrate with light reflection film which brings about few interference fringes.
2. Description of the Related Art
It is known that liquid crystal display devices have been widely used as display devices in various electronic apparatuses because thicknesses can be reduced, power consumption can be reduced, and the like. Such a liquid crystal display device generally has the configuration in which a liquid crystal is encapsulated between a pair of glass substrates, etc., and the peripheries of the substrates are bonded together with a seal member. The electronic apparatus, on which such a liquid crystal display device is mounted, adopts the configuration in which a protection plate is placed on the observation side of the liquid crystal display device, that is, on the side of the observer visually identifying the display, in order to protect the liquid crystal display device from external shock, etc. Such a protection plate is a plate-shaped member made of, usually, a material having light-transmitting property, for example, transparent plastic.
However, it is difficult to make the surface of such a protection plate facing the liquid crystal display device a perfectly smooth surface, and in many cases, fine concavities and convexities exist. When such a protection plate was placed in the liquid crystal display device, there was a problem in that the display quality was degraded remarkably due to the fine concavities and convexities on the surface.
Causes of this degradation of the display quality include that the interval between the substrate and the protection plate on the observation side in the liquid crystal display device varies depending on the concavities and convexities existing on the surface of the protection plate. That is, interference occurs when emitted light from the liquid crystal display device passes through the protection plate corresponding to the aforementioned variations in the intervals and, as a result, the interference fringes occur. Consequently, it is assumed that the degradation of the display quality is brought about by overlapping of the interference fringes and the display image.
In Japanese Unexamined Patent Application Publication No. 6-27481, a reflective liquid crystal display 400 is disclosed as shown in FIG. 26, and in Japanese Unexamined Patent Application Publication No. 11-281972, a reflection transmission combination (transflective) type 500 is disclosed as shown in FIG. 27. In order to reduce occurrence of interference fringes, each of these is provided with a plurality of concavity and convexity structures 404a and 404b (504a and 504b) having different heights, a macromolecular resin film 405 (505) is formed thereon and, furthermore, a continuous corrugated reflection electrode 409 (509) is formed thereon.
Manufacturing processes for liquid crystal display devices having such a reflection electrode are disclosed, and an example is disclosed in FIG. 28. As shown in FIG. 28(a), a resist film 602 is formed over a glass substrate 600 and, thereafter, as shown in FIG. 28(b), exposure is performed through a pattern 604 composed of a plurality of circles having different diameters. Development is performed as shown in FIG. 28(c) and, therefore, convex portions 606a and 606b including a plurality of corners having different heights are placed. Subsequently, as shown in FIG. 28(d), heating is performed to soften the corners of the convex portions and, therefore, rounded-corner convex portions 608a and 608b are formed. As shown in FIG. 28(e), a predetermined quantity of macromolecular resin 620 is put into the space 610 among such concavity and convexity structures in order to make a continuous layer having a corrugated surface and, furthermore, a continuous corrugated reflection electrode 624 is formed on the macromolecular resin film 620 by a lamination means, for example, sputtering.
However, regarding liquid crystal display devices, for example, the reflective liquid crystal display and the reflection transmission combination (transflective) type liquid crystal display device disclosed in Japanese Unexamined Patent Application Publication No. 6-27481, etc., although the masks, in which a plurality of circles having different diameters, etc., have been regularly or partially irregularly arranged, have been used in order to place a plurality of concavity and convexity structures having different heights by the use of ultraviolet exposure and development, it has been difficult to precisely adjust the heights so as to effectively prevent interference of light because of variations in coating thicknesses, etc. Furthermore, since the reflection electrode has been formed on the plurality of concavity and convexity structures having different heights, there have been problems in that breaks and short circuits have been likely to occur, and the like. Regarding the disclosed manufacturing method for the substrate with light reflection film, there have been problems relating to manufacture in that a large number of steps have been required and many items have been required to control.
Therefore, regarding the substrates with light reflection film described in Japanese Unexamined Patent Application Publication No. 6-27481, etc., it has been difficult to effectively prevent the occurrence of the interference fringes and, in addition, it has been difficult to stably and efficiently manufacture such a substrate with light reflection film.
Accordingly, the inventors of the present invention earnestly researched regarding the aforementioned problems, and as a result, found out that when a plurality of convex portions or concave portions are placed on the base material in the substrate with light reflection film and are arranged in the direction of the plane on a random basis without changing the heights of the plurality of convex portions or concave portions substantially, the substrate with light reflection film which brings about few interference fringes can be produced with ease.
That is, it is an object of the present invention to provide a mask for producing a substrate with light reflection film which brings about few interference fringes and which can be produced with ease, such a substrate with light reflection film, a manufacturing method for such a light reflection film, and an electro-optical device provided with such a substrate with light reflection film, and an electronic apparatus provided with such a substrate with light reflection film.